1. Field of the Invention
The present invention relates to injection molding systems and, in particular, a structure for supporting maintenance of an injection molding machine in an injection molding system.
2. Description of the Related Art
In a general injection molding machine, bolts are used to fix components of a mold and the injection molding machine. Also, a mechanism is also used to hold the components by using an apparatus such as an oil hydraulic clamp or magnetic clamp in place of bolts.
When an oil hydraulic clamp is used, the position of the clamp is fixed. Therefore, a fixing position commonly used for a plurality of molds has to be provided. Moreover, when a magnetic clamp is used, it is required to attach a magnetic plate to a mold fixing disc of the injection molding machine. Thus, the thickness of the mold mountable on the machine has to be decreased by the plate thickness of the magnetic plate, or the length of a nozzle has to be increased by the plate thickness of the magnetic plate in order to bring the nozzle of the injection molding machine into contact with the mold. Furthermore, for the oil hydraulic clamp, an expensive apparatus such as a magnetic clamp has to be introduced.
Thus, for production by replacing various molds, fastening with bolts is generally used. Fastening with bolts allows a mold to be easily fixed, and is highly flexible as well as at low cost at the time of introduction. In fastening with bolts, the position and length of a bolt for fixing a mold vary for each mold, and therefore mold replacement is generally performed by hand.
As with mold replacement, the mount positions and required number of, for example, ejector rods, which transfer ejecting motive power to the mold in the injection molding machine, also depend on the structure of the mold. Therefore, the positions and number thereof may vary in accordance with the mold.
Also, as for maintenance of a portion around a nozzle of an injecting apparatus of the injection molding machine, the sizes and positions of bolts for use vary depending on the component type. Therefore, automated attaching and detaching operation is difficult, and dissembling and assembling at the time of maintenance are required to be performed by hand.
It is generally performed that mold replacing operation is automated by combining an oil hydraulic clamp, a magnetic clamp, and mold conveying unit. However, for example, operation of fastening a bolt of a mold or the like is generally performed by humans.
As a method of fixing a mold to a platen, Japanese Patent Application Laid-Open No. 4-135805 discloses a technology of attaching a mold by using a robot including a bolt fastening tool at a wrist. As for bolt attachment and detachment, for example, as is used in, for example, assembling factories for automobiles and so forth, a motor-operated or air-driven impact wrench or the like is attached to a robot to remove a bolt.
Unlike the assembling factories for automobiles and so forth where the same things are assembled, the position of a bolt is changed for each mold in mold replacing operation. While the technology of Japanese Patent Application Laid-Open No. 4-135805 discloses bolt fastening by a robot, the technology does not disclose bolt position recognizing unit or bolt position storage unit. Thus, it may be difficult to address the case in which the position of a bolt is changed for each mold.
Moreover, since maintenance operation is not always being performed but is temporary, installing a machine dedicated to maintenance operation is not effective in view of space, and is also inefficient in operation.